Hydraulics of large diameter gated flexible fluming

Koech, Richard and Smith, Rod and Gillies, Malcolm (2013) Hydraulics of large diameter gated flexible fluming. Biosystems Engineering, 114 (2). pp. 170-177. ISSN 1537-5110

Abstract

Gated flexible or 'layflat' fluming is used in furrow irrigation to supply water to individual furrows. Laboratory experiments were conducted to establish the flow characteristics of these pipes under the low heads and high flow rates typical of furrow irrigation of cotton in Australia. Two different diameters of layflat were used in the study, 222.8 and 425mm. Proprietary 50mm diameter outlets (gates) were installed in the layflat at 1m spacings. Tests were conducted at various pressures and flow rates to determine; the geometric characteristics of the fluming and their relationship to pressure, the friction loss coefficient for the fluming with and without the outlets installed, and the head-discharge characteristic for the outlets. It was shown that the fluming is capable of supplying the desired flow rates (about 6l s-1 per furrow) at pressure heads <1m. The head-discharge characteristic for the proprietary outlets followed a similar form to the standard orifice equation. No evidence was found to suggest that the velocity head played any significant role in determining the outlet discharge. The Hazen-Williams coefficient (CHW) of the fluming with the outlets installed was a low 80 compared to a value of about 140 for the fluming without gates. This clearly illustrates the increase in energy losses caused by the protrusion of the gates into the flow and that these losses far exceed the losses due simply to pipe friction. These experimentally derived coefficients and characteristic equations were used to validate the simulation program GPIPE.


Statistics for USQ ePrint 25343
Statistics for this ePrint Item
Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: © 2012 IAgrE. Published version deposited in accordance with the copyright policy of the publisher.
Faculty / Department / School: Current - Faculty of Health, Engineering and Sciences - School of Agricultural, Computational and Environmental Sciences
Date Deposited: 24 Jun 2014 03:03
Last Modified: 03 Jul 2014 01:24
Uncontrolled Keywords: Australia; characteristic equation; flow characteristic; friction loss; furrow irrigation; geometric characteristics; Hazen-Williams coefficients; high-flow rate; Laboratory experiments; Large diameter; Low head; orifice equation; pressure heads; simulation program; velocity head
Fields of Research : 09 Engineering > 0915 Interdisciplinary Engineering > 091508 Turbulent Flows
07 Agricultural and Veterinary Sciences > 0799 Other Agricultural and Veterinary Sciences > 079901 Agricultural Hydrology (Drainage, Flooding, Irrigation, Quality, etc.)
09 Engineering > 0913 Mechanical Engineering > 091307 Numerical Modelling and Mechanical Characterisation
Socio-Economic Objective: D Environment > 96 Environment > 9609 Land and Water Management > 960905 Farmland, Arable Cropland and Permanent Cropland Water Management
Identification Number or DOI: 10.1016/j.biosystemseng.2012.12.005
URI: http://eprints.usq.edu.au/id/eprint/25343

Actions (login required)

View Item Archive Repository Staff Only